code: def get_checkpoint_file(network, checkpoint_path=DEFAULT_PATH):
      if checkpoint_path is None:
          checkpoint_path = DEFAULT_PATH
      checkpoint_path = get_checkpoint_path(path=checkpoint_path)
      files = tf.gfile.ListDirectory(checkpoint_path)
      network_filename = "{}.ckpt".format(network)
      checkpoint_file = os.path.join(checkpoint_path, network_filename)
      if network_filename not in files:
          download_checkpoint(
              network,
              network_filename,
              checkpoint_path,
              checkpoint_file,
          )
  
      return checkpoint_file
  
file_path: luminoth/luminoth/utils/checkpoint_downloader.py
imports: import click
  import json
  import os
  import requests
  import tarfile
  import tensorflow
  from luminoth.utils.homedir import get_luminoth_home
label_desc: Use image node_id 4 for calling a global function with example usage: get_checkpoint_file(network, checkpoint_path) and returns: checkpoint_file